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141.
Search effectiveness metrics are used to evaluate the quality of the answer lists returned by search services, usually based
on a set of relevance judgments. One plausible way of calculating an effectiveness score for a system run is to compute the
inner-product of the run’s relevance vector and a “utility” vector, where the ith element in the utility vector represents the relative benefit obtained by the user of the system if they encounter a relevant
document at depth i in the ranking. This paper uses such a framework to examine the user behavior patterns—and hence utility weightings—that
can be inferred from a web query log. We describe a process for extrapolating user observations from query log clickthroughs,
and employ this user model to measure the quality of effectiveness weighting distributions. Our results show that for measures
with static distributions (that is, utility weighting schemes for which the weight vector is independent of the relevance
vector), the geometric weighting model employed in the rank-biased precision effectiveness metric offers the closest fit to
the user observation model. In addition, using past TREC data as to indicate likelihood of relevance, we also show that the
distributions employed in the BPref and MRR metrics are the best fit out of the measures for which static distributions do
not exist. 相似文献
142.
Park Heon-Joon Kim Derk-Moon Kim Ki-Seog Ahn Hee-Yoon Kim Dong-Soo 《Journal of Cultural Heritage》2012,13(1):98-102
Architectural heritages are exposed to natural and man-made disasters so that the need for research to prevent disasters has arisen. Cheomseongdae, known as the oldest astronomical observatory in East Asia, displays separation between the members and is tilted to the north-northeast. To diagnose the present conditions and to resolve problems, site investigations are performed. Boring is conducted in the surrounding ground of Cheomseongdae, and noninvasive investigations such as seismic tests and electrical resistivity surveys are conducted as well. The present study proposes a geotechnical engineering approach focused on noninvasive site surveys, and through this, relates current tilted condition of structure and provides information on the stability of Cheomseongdae. 相似文献
143.
Gold nanoparticles (Au NPs) were directly synthesized on the surface of polyvinylsilazane (PVSZ, -[(vinyl)SiH-NH2]-) without use of extra reductive additives. The reductive Si-H functional groups on the surface of cured PVSZ acted as surface bound reducing agents to form gold metal when contacted with an aqueous Au precursor (HAuCl4) solution, leading to formation of Au NPs adhered to silicate glass surface. The Au NPs-silicate platforms were preliminarily tested to detect Rhodamine B (1 μM) by surface enhanced Raman scattering. Furthermore, gold microelectrode obtained by post-chemical plating was used as an integrated amperometric detection element in the polydimethylsilane-glass hybrid microfluidic chip. 相似文献
144.
145.
In a droplet transport based on electrowetting on dielectrics, the parallel-plate configuration is more popular than the single-plate one because the droplet transport becomes increasingly difficult without cover plate. In spite of the improved transport performance, the parallel-plate configuration often limits the access to the peripheral components, requesting the removal of the cover plate, the single-plate configuration. We investigated the fundamental features of droplet transport for the single-plate configuration. We compared the performance of several switching methods with respect to maximum speed of successive transport without failure and suggested nonfloating switching method which is inherently free from the charge-residue problem and exerts greater force on a droplet than conventional switching methods. A simple theory is provided to understand the different results for the switching methods. 相似文献
146.
In three experiments, participants were asked to produce a prescribed temporal sequence of key presses. The number of elements in a key press sequence, the movement time of the elements, and uniformity of the timing elements comprising the sequence were manipulated. If the processing of the sequence structure was independent of the processing of elements comprising the sequence, increasing the number of the elements in the sequence should affect the production of the sequence but not the proficiency with which the individual elements are, produced. Increasing the movement time of the elements, however, should affect the production of the elements but have little, if any, effect on the integrity of the sequence. The findings indicated that increasing the number of elements negatively affected sequence production when the elements were nonuniform but had little or no effect when elements were uniform. Alternatively, element production was affected by movement time but not number of elements. The results of these experiments appear to confirm the independence of sequence and element production. However, Experiment 3, in which the uniformity of the elements was directly contrasted, found strong evidence for coarticulatory influences in the learning processes, whereby the longer and shorter than average elements in the sequence negatively affected the sequence integrity and the production of the individual elements. When faced with a nonuniformn timing pattern, participants appear to elongate or shrink individual elements of a uniform timing pattern to fit the desired sequence requirements. The result is that the longer or shorter than average elements require more practice to produce correctly, tend to regress across retention intervals, and are generally less stable than the elements nearer the average. 相似文献
147.
148.
Stephanie J. Graves Jian Anna Xiong Ji-Hye Park 《The Journal of Academic Librarianship》2008,34(3):202-210
A survey of tenure-track and tenured librarians at ARL libraries provides data on the relationship between parenthood and professorship. Results analyze the impact of the promotion and tenure process on child-bearing and child-rearing decisions. Discrepancies are found based on gender, tenure status, and family status. 相似文献
149.
Background:One-legged pedaling is of interest to elite cyclists and clinicians.However,muscular usage in 1-legged vs.2-legged pedaling is not fully understood.Thus,the study was aimed to examine changes in leg muscle activation patterns between 2-legged and 1-legged pedaling.Methods:Fifteen healthy young recreational cyclists performed both 1-legged and 2-legged pedaling trials at about 30 Watt per leg.Surface electromyography electrodes were placed on 10 major muscles of the left leg.Linear envelope electromyography data were integrated to quantify muscle activities for each crank cycle quadrant to evaluate muscle activation changes.Results:Overall,the prescribed constant power requirements led to reduced downstroke crank torque and extension-related muscle activities(vastus lateralis,vastus medialis,and soleus)in 1-legged pedaling.Flexion-related muscle activities(biceps femoris long head,semitendinosus,lateral gastrocnemius,medial gastrocnemius,tensor fasciae latae,and tibialis anterior)in the upstroke phase increased to compensate for the absence of contralateral leg crank torque.During the upstroke,simultaneous increases were seen in the hamstrings and uni-articular knee extensors,and in the ankle plantarflexors and dorsiflexors.At the top of the crank cycle,greater hip flexor activity stabilized the pelvis.Conclusion:The observed changes in muscle activities are due to a variety of changes in mechanical aspects of the pedaling motion when pedaling with only 1 leg,including altered crank torque patterns without the contralateral leg,reduced pelvis stability,and increased knee and ankle stiffness during the upstroke. 相似文献
150.
Droplet-based microfluidic technology has enabled the production of emulsions with high monodispersity in sizes ranging from a few to hundreds of micrometers. Taking advantage of this technology, attempts to generate monodisperse emulsion drops with high drug loading capacity, ordered interfacial structure, and multi-functionality have been made in the cosmetics industry. In this article, we introduce the practicality of the droplet-based microfluidic approach to the cosmetic industry in terms of innovation in productivity and marketability. Furthermore, we summarize some recent advances in the production of emulsion drops with enhanced mechanical interfacial stability. Finally, we discuss the future prospects of microfluidic technology in accordance with consumers'' needs and industrial attributes. 相似文献